Horizontal centrifugal casting machine

ABSTRACT

A horizontal centrifugal casting machine is described wherein a sectionalized mold for casting a cylindrical structure, e.g., a finned motor frame, is assembled, the structure cast and the mold sections stripped from the cast structure in an entirely automated process. The casting machine includes a plurality of arcuately shaped mold sections mounted upon jaws capable of being secured to pistons of pulling cylinders. With the pistons extended, the mold sections form a substantially cylindrical structure and dual annular rings having a tapered radially inner face are traversed axially along a tapered outer portion of the jaws to fixedly secure the mold sections in position. After disengagement of the pistons, the mold is rotated by a high speed drive motor whereafter a ladle containing molten metal is inserted axially within the mold and the ladle is tilted to pour the molten metal into the mold. The ladle then is withdrawn and a mandrel assembly supporting the ladle, an expandable arbor and a mold coating device is rotated to register the expandable arbor with the mold. The high speed drive motor then is de-energized and the mold stopped at a predetermined angular position using a low speed drive motor. After the expandable arbor is inserted axially within the mold and the arbor expanded to engage the interior of the cast cylindrical structure, the pistons of the pulling cylinders are driven radially inward to engage the outer surface of the jaws and the annular rings are released to permit the pistons to strip the mold from the cast structure. The cast then is removed from the interior of the stripped sections and the open jaws are coated with casting lubricant permitting the casting cycle to be repeated. To obtain optimum quality in casting finned aluminum motor frames, the rate of rotation of the ladle during the pour should vary to effect a more rapid rate of angular displacement at the initiation and termination of pouring metal from the ladle than at the middle of the pour to produce a constant flow of metal from the ladle.

United States Patent [191 Baumann et al.

[ July 23, 1974 1 HORIZONTAL CENTRIFUGAL CASTING MACHINE [75] Inventors:Frederick William Baumann, Scotia',

Bernard Ceasar Kaczkowski, Schenectady; George Mowry Rosenberry, Jr.,Elnora; William R. Smith, Ballston, all of NY.

[73] Assignee: General Electric Company,

Schenectady, NY.

[22] Filed: Aug. 4, 1972 [2]] Appl. No.: 277,920

FOREIGN PATENTS OR APPLICATIONS 488,074 12/1953 Italy 425/435 PrimaryExaminer-J. Spencer Overholser Assistant Examiner-John E. RoethelAttorney, Agent, or Firm-Vale P. Myles [57] ABSTRACT A horizontalcentrifugal casting machine is described wherein a sectionalized moldfor casting a cylindrical structure, e. g., a finned motor frame, isassembled, the

structure cast and the mold sections stripped from the cast structure inan entirely automated process. The casting machine includes a pluralityof arcuately shaped mold sections mounted upon jaws capable of beingsecured to pistons of pulling cylinders. With the pistons extended, themold sections form a substantially cylindrical structure and dualannular rings having a tapered radially inner face are traversed axiallyalong a tapered outer portion of the jaws to fixedly secure the moldsections in position. After disengagement of the pistons, the mold isrotated by a high speed drive motor whereafter a ladle containing moltenmetal is inserted axially within the mold and the ladle is tilted topour the molten metal into the mold. The ladle then is withdrawn and amandrel assembly supporting the ladle, an expandable arbor and a moldcoating device is rotated to register the expandable arbor with themold. The high speed drive motor then is de-energized and the moldstopped at a predetermined angular position using a low speed drivemotor. After the expandable arbor is inserted axially within the moldand the arbor expanded to engage the interior of the cast cylindricalstructure, the pistons of the pulling cylinders are driven radiallyinward to engage the outer surface of the jaws and the annular rings arereleased to permit the pistons to strip the mold from the caststructure. The cast then is removed from the interior of the strippedsections and the open jaws are coated with casting lubricant permittingthe casting cycle to be repeated. To obtain optimum quality in castingfinned aluminum motor frames, the rate of rotation of the ladle duringthe pour should vary to effect a more rapid rate of angular displacementat the initiation and termination of pouring metal from the ladle thanat the middle of the pour to produce a constant flow of metal from theladle.

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saw 12 or 15 FILL LADLE WITH REQUIRED QUANTITY OF MOLTEN METAL DRIVEMOLD SECTIONS INTO CYLINDRICAL CONFIGURATION DRAW LOCK RINGS AXIALLYINWARD TO LOCK SECTIONS IN POSITION DISENGAGE AND WITHDRAW PULLINGPISTONS FROM MOLD SECTIONS ROTATE MOLD AND CIRCULATE COOLANT INTO MOLDINSERT LADLE INTO MOLD AND POUR STOP MAIN MOLD DRIVE AND INDEX MOLD WITHPULLING PISTONS WITHDRAW LADLE AND ROTATE MANDREL ASSEMBLY TO INDEX THEARBOR WITH MOLD INSERT ARBOR WITHIN MOLD AND EXPAND ENGAGE PULLINGPISTONS WITH MOLD SECTIONS AND STRIP FROM CAST REMOVE CAST FROM INTERIOROF MOLD SECTIONS AND INDEX SPRAY HEAD WITH SECTIONS SPRAY STRIPPED MOLDSECTIONS WHILE DRIVING SPRAY HEAD THEREIN RETRACT SPRAY HEAD AND INDEXLADLE WITH MOLD I withdraw the cast pipe from the mold.

HORIZONTAL CENTRIFUGAL cssnnc MACHINE This invention relates toahorizontal centrifugal casting-machine for casting finned cylindricalstructures and inparticular, to a casting machine wherein asectionalized mold is assembled into a cylindrical configuration; thestructure is centrifugally, cast within the mold and the mold strippedfrom the structure in a sub stantially automated process.

In the manufacture of dynamoelectric machines, "a number of diversetechniques heretofore have been proposed and/or utilized to fabricatemachine frames dependent upon such diverse factors asthe size and numberof frames to be cast. For example, high pressured die casting techniqueshave been employed to produce cylindrical frames below approximatelyinches indiameter on a high volume basis while machine frames above lOinches in diameter generally have been formedcommercially by sandcasting or extrusion techniques.

While centrifugal casting has been known for many years,centrifugalcasting machines primarily have been limited to castingstructures having a'smooth outer surface, such as metal pipes, or forapplying interior linings to preformed objects, e.g., casting brakelinings along the interior of brake drums. Foreitample, a centrifugalcasting machine is described'in U.S. Pat. No.

1,917,872 for casting brake drum linings'by inserting a ladleinto ametal drum retained in position within a plurality of arcuately shapedsegments and gradually tilting the ladle topour metal at'a uniform rateinto the drum. Because the mold is separate from the centrifugal castingmachine and forms a part of the finished product, there is no need tostrip the mold from the centrifugally cast metal. A highly automatedcentrifugal casting machine for producing. smooth surfaced pipes also isshown-in U.S. Pat. No. 3,457,986 wherein a plurality of molds aremounted along the periphery of a rotatable turret and the turret isrevolved to register the individual moldswith circularly disposedstations, i.e., a centrifugal casting station, a spray coolingstahowever, is Ispecifically designed for smooth surfaced objects andwould not be suitable for casting finned structures because of theuse ofexpandable tongs to It also has been proposed (i.e., in Baumann et alU.S. Pat. applications, Ser. No. 220,285 entitled Horizontal CentrifugalCasting Machine" and Ser. No. 220,286 entitled "A Dismemberable Mold ForCentrifugally Casting Pinned-Structures," both filed Jan. 24, 1972, nowU.S. Pat. No. 3,744,707, and both having the same assignee as thisapplication), that a sectionalized mold be seated upon horizontalrollers of a centrifugal casting machine to permit substantiallyautomated casting of finned cylindrical structures. Because the mold isnot fixedly secured to the casting machine, the mold can be lifted fromthe rollers by a crane and transported to a stripping machine (such asis described in LaBahn et al U.S. Patent application, Ser. No. 220,280,entitled Method and Apparatus For Automatically Stripping ASectionalized Mold From A Cast" and Baumann et al U.S. Patentapplication, Ser. No. 220,279 entitled "Automated Method OfManufacturing Finned Machine Frames," now U.S. Pat. No. 3,741,278, bothfiled tion, apipe'withdtawal station, etc., to effect the se quentialsteps. of the casting process. Such machine,

Jan. 24, 1972 and having the same assignee as this application) to stripthe sectionalized mold from the underlying centrifugally cast structure.While the centrifugal casting equipment and casting methods disclosed inthe foregoing applications are highly'suitable for casting largediameter finned cylindrical structures, the production rate is somewhatlimited by the necessity for transferring the mold from the castingmachine to the stripping machine. Moreover, because the crane requiredto transfer the mold from the casting machine to the stripping machinenormally is under the control of an operator and because the heat of themold makes manual assistance in the transfer difficult, substantiallabor is required to complete the process notwithstanding the automatednature of each individual machine utilized for casting.

It is therefore an object of this invention to provide a highlyautomated centrifugal casting machine wherein the mold is assembled, thestructure cast and the mold stripped from the cast in a single machine.

It is also an object of this invention to provide a centrifugal castingmachine capable of producing a. large quantity of cast finned structureson a substantially automated basis. i It is a further object of thisinvention to provide a centrifugal casting machine having a mold lockingassembly capable of securely fastening the individual mold sections intoa composite unit for casting while permitting ready disengagement fromthe mold for stripping the mold sections from the cast structure.

It is a further object of this invention to provide an automatedmethod-of casting finned cylindrical structures and stripping'the mold:from the cast structures.

A horizontal centrifugal casting machine for casting cylindricalstructures in accordance with this invention generally includes aplurality of arcuate mold sections having interlocking edges and meansconnected to'the mold sections for moving the sections intojuxtaposition to form a cylindrical mold capable of confining the liquidmaterial to be cast. Means also are provided for connecting a rotarydriveto the cylindrical mold for rosections from the cast and to preventfracturing of the cast structure during stripping, the casting machinepreferably also includes means for inserting an arbor within the castcylindrical structure and means for expanding at least a portion of thearbor in a radial direction to contact the interior of the caststructure prior to stripping the mold sections from the cast. When themolten-material is poured into the rotating mold from a ladle, suitablemeans desirably are included within the machine to tilt the ladle at avariable rate during the pour, Le, a more rapid angular displacement ofthe ladle is desirable at the beginning and end of the pour than at themiddle of the pour, in order to produce constant flow of metal from theladle and high quality in the finished cast product.

Although this invention is described particularity in the appendedclaims, a more complete understanding FIG. 3 is a view of the apertur'edplate utilized in the speed sensing and mold positioning assembly,

FIG. 4 is an enlarged sectional ,view of the speed sensing and moldpositioning assembly,

FIG. 5 is a sectional view taken along lines 55 of FIG. 1 to illustratethe 'I -s'haped groove wherein the gripping jaws slide,

FIG. 6 is an enlarged view of the lock rings utilized to secure the moldin position for casting,

FIG. 7 is an isometric view of the mold in a machine mounted assembly,

FIG. 8 is a view depicting the serial connection of the coolant hoses tothe mold sections,

FIG. 9 is a sectional view of'themold pulling assembly,

FIG; 10 is a sectional view of the ladle: rotation mechanism,

FIG. 11 is a view of the variable the ladle rotation mechanism.

FIG. 12 is a graph illustrating the variation of rate of angulardisplacement of the ladle with the quantity of aluminum poured from theladle, V g

FIG. 13 is a sectional view of the expandable arbor,

FIG. 14 is a view of the I4-14 of FIG. 13,

FIG. 15 is a sectional view of the lubricantspray mechanism of thecasting machine, a

FIG. l6is an' elevation view of the main turntable,

FIG. 17 is aplanview of the main turntable to illustrate the speedcontrol and positioning mechanism of the turntable FIG. 18 is a view ofthe'main turntable rotary drive,

FIG. 19 is a sectional view of the mechanical registration piston of themain turntable,

FIG. 20 is a sectional view taken along lines 20-20 of FIG. 17toillustrate the limit switches controlling table rotation,

FIG, 21 is aflow chart showing the sequential operation of thecasting-machine, and

FIG. 22 (a-c) is an electrical diagram of a circuit suitable forcontrolling the operation of the machine.

A horizontal centrifugal casting machine 10 in accordance with thisinvention is shown in FIG. 1 and generally comprises a drive andtransmission unit 11, a mold assembly and stripping unit 12 and amandrel assembly 13. The mandrel assembly (illustrated also in FIG. 2)is rotatable to axially register ladle 14, expandable arbor 15 orlubricant spray head 16 with the mold and the entire mandrel assembly ismounted upon a carriage l7axially traversable along rails 18 to permitin scrtion of the registered mandrel component axially into the mold.

DRIVE AND TRANSMISSION UNIT The main drive for horizontal centrifugalcasting machine 10 is provided by drive motor 19, e.g., a solid obtainedfrom the following.

pour rate'control oi arbor taken along lines 35 motor is operated at arotary speed of approximately 900 rpm to produce a speed ofapproximately 500 rpm in rotary face plate 20 to which the arcuatesections of centrifugal mold 2! are secured. Because the drive andtransmission unit are subject to multiple starting and stopping duringoperation, motor I9 desirably is cooled by a blower unit 23 whichincludes fan 24 driven by motor 25 and suitable ducting 26 communicatingthe drive motor interior with the external environment.

The drive end 27 of main drive motor 19 rotates a pulley 28 drivingflexible belts 29 to 'apply torque to a larger diameter pulley 30 toobtain the desired reduction in speed between the drive motor andcentrifugal mold 21. Because the belt load is too great for directapplication to main shaft '31 of the drive and transmission unit,torquetransmitted through belt 29 is transferred to the main shaft through aconventional bearing block assembly 32'and standard coupling unit 33. Asis shown in FIG. I, the outer housing 34 of bearing block assembly 32 isfixedly secured to base 35 of the casting machine to support the beltload while a pair of bearings 36 permit rotation of shaft 37 within thebearing block assembly to transmit rotary force through coupling unit 33to main shaft 31. The torque applied to main shaft 31 through couplingunit 33 then is transmitted to rotary face plate 20 secured to thehollow main shaft by bolts 38 to permit rotation of centrifugal mold 21mounted to'the face plate (as will be more fully ex plainedhereinafter).

The speed of main shaft 31 is monitored by a speed sensing and moldpositioning assembly 39 (illustrated in FIGS. 3 and 4) which includes aselectively apertured wheel 40 mountedupon the shaft to pass betweenthree proximity switches 41-43 secured to supports 44 mounted to block45 on base 35. Uppermost proximity switch 41 is radially registered withsix 'arcuately spaced apertures 46 inwheel 40to measure the rotary speedof shaft 31- by counting the number of actuations of. proximity switch41 within'a-t'ixed period of time while lower proximity switch 42registered with radially outer semicircular lip 47 of wheel 40 isemployed to determine whether shaft 31 is rotating by sensing continuedactuations of the proximity switch. The third proximity switch 43 servesto position rotary face plate 20 (and mold 21 mounted thereon) at aparticular angular orientation with pulling assembly 48 (illustrated inFIG. 1) of the casting machine by aligning the proximity switch withprotrusion 49 extending axially outward from wheel 40. Proximityswitches, to achieve the foregoing results, are well known in the artand can be obtained commercially from the General Purpose ControlDepartment of the General Electric Company.

To obtain the desired registration between protrusion 49 and proximityswitch 43 (and the resultant registration between centrifugal mold 21and pulling assembly 48), a small drive motor 50 (illustrated in FIG. I)is connected to the opposite drive end of the shaft of main drive motor19 through a gear reducer 51 and an electric clutch 52 topennit slowrotation of main shaft 31 after termination of mold rotation at the endof a cast. as observed by proximity switch 42. Thus, with drive motor 19stationary after the completion of a centrifugal cast, electricalclutch-52 is engaged and small drive motor 50 is energized 'to slowlyrotate shaft3l through main drive motor 19 until protrusion 49 isregistered with proximity switch 43 at which time energization of thesmall drive motor is terminated and the motor electric brake is'engagedto stop rotation of the mold. Clutch 52 then is disengaged, and thetapered piston of hydraulic cylinder 22 is inserted into a slot inrotary face plate .to' lock the plate in position.

Main shaft 31 is utilized not only to transmit torque to rotaryfaceplate 20 but also as a conduit to transmit fluid coolant to mold 21mounted upon the face plate. The fluid coolant, typically water, entersaxially outer annular chamber 53 through aperture 54 in water jacket 55surrounding the end of shaft 31 remote from the mold and the coolantflows through bore 56 in the shaft to a central pipe 57 for axialtransmission along the shaft. The fluid coolant then advances intoannular chamber 58 formed between partition 59 and plug 60 whereafterthe coolant flo'ws radially outward through aperture 61 in the shaft andflexible hoses 62 to pass serially through the-four'individual sectionsforming mold 21 (as will be more fully explained hereinafter withreference to FIG. 8). The coolant then returns through aperture 63 toaxial flow channel 64 between shaft 31 and pipe 57 to return to annularchamber 65 by way of radial bore 66 in shaft 31. From annular chamber65, the

plate 20 thereby locking-the four mold sections secured to therespective onesof orthogonally disposed jaws 86 into a compositecylindrical unit. Limit switchesBS are mounted upon the exterior ofhousing assembly 72 to measurethe outward extent of pistons 78, i.e., byactuation of the limit switches by vanes 89 carried upon rod 90 mountedon plate 79.

Because the axially outer and inner lock rings, identified by referencenumerals 84a and 84b, respectively,

of the mold locking unit may not contact tapered'faces 85a and 85b ofmold gripping jaws 86 with equal force due to unequal thermal expansionof the jaws during casting, axially outer lock ring 840 is driven by anindividual spring biasing means, such as theBellville washers 92, shownin FIG. 6, to compensate for the effects of thermal expansion. Thus,although rods 82 produce an equal axial advancement of tapered lockrings 84a and 84!: upon actuation of hydraulic cylinder 75, thermalexpansion of gripping jaw'86 may produce a higher clamping force betweenone ring, i.e., inner ring 84b, and tapered face 85b of the gripping jawthen occurs between outer ring 840 and the gripping jaw. By dimensioningthe inner radius of ring 84;: to engage the grippingjaw' before ring84b, Bellville washer 92 situated adjacent ring Mo on rod 82 can absorbthe axial load as axially inner ring 84 b is driven into firm contactwith the associated tapered face on gripping jaw 86 to equalcoolantflows through aperture 67 within water jacket 55 to return to a heatexchange and pumping unit (not shown) for recirculation through themold. A partition 68 serves to separate the streams of circulatingcoolant in the adjacent annular chambers at the endof shaft 31 whileconventional face seals 69 inhibit leakage of coolant adjacent theshaft. v

Main shaft 31 is supported at the driven end .of the shaft by aspherical bearing 70 while a tapered roller bearing 71 is situated atthe drive end of the shah to absorb both radially and axially directedshaft loads. In conventional fashion, tapered roller-bearing 71 ispositioned between shaft 31 and housing assembly 72 at a fixed axiallocation while spherical bearing 70 is axially slidable between theshaft and housing assembly to inhibit axialloading of the bearing. Bothbearings are lubricated by oil circulating between the rotating shaftand the stationary housing assembly by way of oil intake and exhaustorifices 73 and 74, respectively,

within the housing assembly.

MOLD ASSEMBLY AND STRIPPING UNlT A pair of hydraulic cylinders 75mounted on plate 76 fixedly secured to base 35 serve to reciprocallydrive mold locking unit 77 in an axial direction thereby securing mold21 in position for casting. To effect locking of the mold, pistons 78within cylinders 75 reciprocally drive annular plate 79 and thereciprocal motion of the plate is transmitted through the radially outerraceway of tapered roller bearing 80m axially traverse the rotarybearing members and the inner raceway of the bearing along shaft 31.Because the inner raceway of bearing 80 also forms an integral part ofback plate 81, the back plate and rods 82 fixedly secured along theperiphery of the back plate also are uaversed in an axial direction byactuation of pistons 78. Axial movement of rods 82 draws the taperedannular face 83 of lock rings 84 against the tapered radially outerfaces 85 of mold gripping jaw 86 to radially slide the jaws within aT-shaped aperture 87 (shown in FIG. 5) of rotary face ize the forcedistribution at axially opposite ends of the assembled mold.

A sectionalized centrifugal mold 21 preferred for utilization in thisinvention is depicted in H6. 7-in' a machine mounted configuration,i.e., with associated gripping jaws 86 of the casting machineflhe moldpreferably is formed of four arcuate sections 2lq-2ld havinginterlocking axial edges 93 to mate upon juxtaposition of the sectionsthereby forming a composite mold capable of retaining molten metaltherein. The interlocking edges 93 of mold 21 are similar to the edgeconfiguration of the mold disclosed inBaumarm et al U.S.' PatentApplication, Ser. No. 220,286 (the disclosure'of which is incorporatedherein by reference). The edges of mold 21, however, are designed-to bedisengaged or engaged upon simultaneously moving all four sections alongperpendicularly oriented axes. To obtain the ready dismemberment of themold while} inhibiting leakage of molten metal from the mold, twodiametrically opposite mold sections, i.e., sections 210 and 21c, areprovided with longitudinal edges having an angular, preferablyorthogonal, step 93a which functions as a seat for the longitudinaledges 93!: of the adjacent mold sections. The radially inward extendinglips 94 at the axial ends adjacent mold sections also have edges 940with a complimentary angular taper, preferably radial. to snugly mateupon juxtaposition of the mold sections.

electric machines, the interior of each mold section preferably isnotched, in conventional fashion, to form a plurality of triangulargrooves 91 extending in a substantially parallel direction into eachmold section to produce the cooling fins desirable for the cast framewithout substantially inhibiting stripping of the mold sections from theframe. To effect such result, the width of the grooves should taper at asuitable angle, e.g., .030/in. n 230, with penetration into the sidewallof the mold.

Each mold section is individually secured to a mold gripping jaw of thecasting machine by bolts 95 and a v7 1 suitable fluid connector,preferably a commercially available quick disconnect connector 96 and anelbow 97 (shown in FIG. 8) admits fluid coolant from flexible hoses 62to the region between the mold section and the jaw fixedly securedthereto. Preferably, the coolant is circulated in dual streams seriallythrough the composite mold jaw units (as shown in FIG. 8) beforereturning to'flow chamber 64 in shaft 31 for return to the heat exchangeand coolant pumping unit associated with the machine.

Because lock rings 84 clamp the mold sections into a composite unit, noprovision (other than tapered face 85 on the mold gripping jaws) isrequired along the outer periphery of the mold sections to secure onemold section to the other.'Four cars 99, however, (shown in FIG. 7) areprovided on each mold section to maintain the sections in juxtapositionin order to facilitate changing molds within the casting machine.

Thus, the change the moldfor a new frame size, pins 98 can be insertedthrough the ears of the mold sec.- tions to maintain the sections injuxtaposition whet-eatter the composite unit may be supported upon arborof mandrel assembly 13. Mandrel assembly carriage 17 then is movedaxially into the machine permitting the mold sections to be'bolted togripping jaws 86-of the machine. The pins retaining the mold sections injuxtaposition then can be manually removed and the arbor withdrawnaxially from the mold to permit the initiation of casting. As was statedearlier, each gripping jaw 86 to which the individual mold sections aresecured has a tapered radially outer face 85 at axiallybppositeends'ofthe mold to permit the application of a radially inward force to themold sections upon the axial traversal-of lock rings 84 across thefaces. One edge of the jaw, the axially inner edge, has a T-shapedprotrusion 100 to be slidably-received within T-shaped aperture 87 ofrotary face plate to permit the jaw to slide in a radial direction. Theradially outer face of each jaw also has apulling bracket 101 forengagement with .-pistons 102 (shown in FIG. 1) of hydraulic pullingassemblies 48 fixedly secured to the stationary main back plate. 104 ofthe centrifugal casting machine;

The pulling assembly utilized to position the mold I sectionsforengagement by lock rings 84and for stripping the mold sections from thecast is illustrated more clearly in FIG. 9 and generally comprises alarge hydraulic pulling cylinder 105, inder, fixedly secured to backplate 104 by brackets 106 and angles 106a. Piston 102 of the pullingcylinder has a tapered bifurcated member 107 threadedly engaged at theforward end of the piston to engage pulling brackets 10! along theradially outer face of gripping jaws 86 while an elongated bracketassembly 108 extends outwardly from bifurcated member 107 to supportsmall diameter piston cylinder 109 which drives dual lockpins 110through aligned apertures 111 in the bifurcated member and the pullingbrackets of the jaws upon admission of hydraulic fluid to the smalldiameter cylinder. Dual limit switches switches ll2'and1l3 also aremounted along the outer housing of small diameter cylinder 109 to beengaged by lockpins 110 to indicate the position of the lockpinsrelative to bifurcated member 107. Similarly, piston 102 of the largepulling cylinder also carries a lower platform 114 having dual guiderods llS mounted thereon to actuate limit switches 116 and 117 by vanes118 mounted on the guide rods toindicatc the extent of piston 102 towardthe mold. in order to permit both the positioning of the four arcuatesections of mold 21 into a cylindrical structure prior to casting, andthe stripping of the mold sections simultaneously from the cast, fourpulling cylinders 105 are mounted at 90 intervals about main back plate104 to radially align bifurcated members 107 with pulling brackets 101of gripping jaws 86.

' To assure that the fourpulling pistons operate simultaneously duringstripping of the mold from the cast, the four pulling cylinders are fedhydraulic fluid through commercially available flow dividers (not shown)to synchronize thepulling of the mold sections from the castnotwithstanding differing adhesive forces between the cast and theseparate mold sections. Flow dividers to achieve this result typicallyinclude four hydraulic pumps having a single interconnected shaft toassure the. pumping of equal quantities of hydraulic fluid to each ofpulling cylinders ,105. Thus, all the pulling pistons are withdrawn intotheir respective cylin- V ders at a uniform rate and there issubstantially no withdrawal until all mold sections are broken loosefrom the a can be connected in series in cast. a Y

Should 'theslip. rate of the pumps forming the hydraulic fluid flowdivider'become excessive, two flow diviers the hydraulic lines, e .g.,

a flow divider capable of pumping seven gallons'per e.g., a 6 inchdiameter cylminute per cylinder could be serially connected with a flowdivider capable of pumping 35 gallons per minute per cylinder. The lowervolume flow divider-then functions to reduce the slip between pullingpistons until the mold sections are disengaged from the cast whereafteralsuitable valve by-passing the lower volume flow divider oould beactuated to permit a more rapid synchronized withdrawal of the pullingpistons into their respective cylinders'under the control of the highervol ume flow divider.

MANDREL ASSEMBLY truding outwardly frorn'an upwardly extendingcenterpost 120 at angularlydisplaced locations, shown at 90 intervals,to permit axial registration of each of the outwardly extendingcomponents with the assembled mold upon rotation of the centerpost.Ladle l4 issubstantially identical to the ladle described in heretoforecited Baumann et al U.S. Patent Application Ser. No. 220,285 (thedisclosure of which is incorporated herein) and generally includes acylindrical vessel 121 having a ceramic lining 122 and a metallic outersheathing 123. In conventional fashion, a rectangular 'opening 124 isprovided along the top of the ladle to admit and remove molten metalfrom the ladle and the ladle is secured to a rotatable shaft 125 topermit tilting of the ladle when discharge of molten metal from theladle is desired. A back plate 126 also is mounted be tween the ladleand rotatable shaft 125 to mate with opening 127 in hood assembly 128 toentirely enclose the rotating mold during the pouring of molten metalinto the mold. V

Tilting of the ladle to pour molten metal therefrom is accomplishedutilizing ladle rotating mechanism 129 (illustrated in FIG. 10 andlllwhich mechanism gen erally includs a hydraulic cylinder 130 fixedlysecured within the mandrel assembly for driving rack 131

1. A horizontal centrifugal casting machine permitting the sequentialcasting of a plurality of finned cylindrical structures, said machinecomprising a rotary drive including a rotary face plate, a plurality ofseparable mold sections having interlocking longitudinal edges, each ofsaid sections being movably secured to said face plate, means connectedto each of said mold sections for moving said sections radially relativeto said face plate to arrange the sections in juxtaposition to form acylindrical mold capable of confining liquid material to be cast thereinand for moving said sections apart to free material cast in the mold,said means for moving said sections being connected to each of said moldsections and being operable to move said sections to form said mold,means connecting said rotary drive to said cylindrical mold to permitrotation of said mold, means for pouring molten material into said moldduring rotation of said mold to cast said cylindrical structure andmeans for stripping said mold sections from said cast to produce afinned cylindrical structure independent of the mold into which saidmolten material was poured.
 2. A horizontal centrifugal casting machineaccording to claim 1 further including means for inserting an arborwithin said mold while it is secured to the face plate subsequent tocasting said cylindrical structure and means for expanding at least aportion of said arbor radially outward to contact the interior of saidcast structure prior to stripping of said mold sections from said caststructure.
 3. A horizontal centrifugal casting machine permitting thesequential casting of a plurality of finned cylindrical structures, saidmachine comprising a rotary drive, a plurality of mold sections havinginterlocking longitudinal edges, means connected to each of said moldsections for moving said sections into juxtaposition to form acylindrical mold capable of confining liquid material to be cast, meansconnecting said rotary drive to said cylindrical mold to permit rotationof said mold, means for pouring molten material into said mold duringrotation of said mold to cast said cylindrical structure and means forstripping said mold sections from said cast to produce a finnedcylindrical structure independent of the mold into which said moltenmaterial was poured, including means for inserting an arbor within saidmold subsequent to casting said cylindrical structure and means forexpanding at least a portion of said arbor radially outward to contactthe interior of said cast structure prior to stripping of said moldsections from said cast structure, wherein said means for pouring moltenmaterial into said cylindrical mold includes ladle means having anopening therein and means for tilting said ladle to pour molten materialfrom said opening, said ladle means and said arbor extending outwardlyfrom a common rotatable mandrel.
 4. A horizontal centrifugal castingmachine according to claim 1 further including tapered rings forclamping each of said mold sections into a cylindrical mold, said ringsbeing axially movable relative to said cylindrical mold to apply radialforce to said mold sections by wedging said tapered rings respectivelyagainst tapered portion of the outer periphery of the mold sections ataxially inner and outer locations thereon, and biasing means driving atleast one of said tapered rings against the tapered portions of the moldsections to equalize the radial pressure produced by the individualrings at said inner and outer locations.
 5. A Horizontal centrifugalcasting machine for casting finned cylindrical structures comprising arotary drive, a plurality of arcuately displaced mold sections, meansfor moving said mold sections into juxtaposition to form a closedcylindrical mold, means connecting said rotary drive to said cylindricalmold to permit rotation of said mold, means for pouring molten materialwithin said mold during rotation to centrifugally cast the finnedcylindrical structure therein, means for registering said cast with anexpandable arbor, means for inserting said arbor within said cylindricalmold, means for expanding at least a portion of said arbor radiallyoutward to contact the interior of said cast structure and means forstripping said mold sections from said cast structure with said arbor insaid cast structure, said means for stripping comprising a plurality ofpulling assemblies (48) mounted at spaced intervals on the castingmachine around the periphery of said mold, each of said pullingassemblies having a piston (102) that is reciprocally operable to engagepulling brackets (101) mounted on the respective mold sections, and amold positioning assembly (39) that is operable to position each of saidpulling assembly pistons in alignment, respectively, with one of themold pulling brackets after material has been cast in the mold.
 6. Ahorizontal centrifugal casting machine according to claim 5 furtherincluding means for circulating a liquid coolant in thermal contact withsaid mold sections to remove heat therefrom during casting.
 7. Ahorizontal centrifugal casting machine according to claim 5 furtherincluding means for registering said stripped mold sections with alubricant spray head, means for traversing said spray head axiallywithin said sections, and means for spraying lubricant along theinterior of said mold sections during said traversal prior to movingsaid sections into juxtaposition for a subsequent cast.
 8. An inventionas defined in claim 5 including an auxiliary motor (50) mounted on saidcasting machine and coupled to selectively rotate said rotary driveresponsive to signals generated by said mold positioning assembly (39)thereby to move the pulling assembly pistons into alignment with themold pulling brackets.
 9. A horizontal centrifugal casting machineaccording to claim 5 wherein said cylindrical mold is formed of fourarcuate sections having a plurality of axially extending grooves notchedtherein in a substantially parallel direction, and said means forstripping said mold sections from said cast include gripping means forfixedly engaging the radially outer surface of each of said four arcuatesections and means for simultaneously actuating said gripping means tostrip said sections from said cast structure by applying a force to eachsaid section in a direction perpendicular to the axis of the cylindricalmold.
 10. An invention as defined in claim 9 wherein said means forsimultaneously actuating the gripping means comprises means ofsynchronizing the pulling forces applied to each of the mold sections bysaid piston thereby to withdraw all of the pulling pistons away from theaxis of rotation of said mold at a uniform rate.
 11. An invention asdefined in claim 10 wherein each of said pistons is mounted respectivelyin a hydraulic cylinder, and wherein said means for synchronizing thepulling forces comprises a flow divider operably connected to thehydraulic supply lines mounted on said machine to supply actuating fluidto each of said cylinders.
 12. A horizontal centrifugal casting machinefor casting finned cylindrical structures comprising a rotary drive, aplurality of arcuately displaced mold sections, means for moving saidmold sections into juxtaposition to form a closed cylindrical mold,means connecting said rotary drive to said cylindrical mold to preventrelative movement therebetween and to permit rotation of said mold,means for pouring molten material within said mold during rotation tocentrifugally cast the finned cylinDrical structure therein, means forregistering said cast with an expandable arbor, means for inserting saidarbor within said cylindrical mold, means for expanding at least aportion of said arbor radially outward to contact the interior of saidcast structure and means for stripping said mold sections from said caststructure with said arbor in said cast structure wherein said means forpouring molten material into said closed cylindrical mold includes aladle and means for tilting said ladle to pour molten material from saidladle into said mold, said ladle and said expandable arbor being mountedupon a common vertically disposed mandrel, and said means forregistering said cast structure with said expandable arbor includesmeans for rotating said mandrel to axially align said expandable arborwith said cast structure and means for producing axial motion betweenaaid mandrel and said cast structure to insert said expandable arborwithin said cast structure.
 13. A horizontal centrifugal casting machineaccording to claim 12 wherein said expandable arbor includes a pluralityof arcuately shaped plates, each of said plates being individuallydriven into contact with the interior of said cast structure uponexpansion of said arbor.
 14. A horizontal centrifugal casting machinefor casting finned cylindrical structures comprising a rotary drive, aplurality of radially movable arcuate sections, said sections beingcapable of forming a cylindrical mold upon a radial traversal of saidsections to a juxtaposed position, drive means secured to the outerperiphery of said sections for radially traversing said sections into asubstantially closed cylindrical disposition tapered lock ring meanssituated adjacent the outer periphery of said mold sections, means forproducing axial movement between said tapered lock ring means and aradially tapered surface on the outer periphery of said mold sections toapply a radial inward force upon each of said mold sections to lock saidsections into a closed cylindrical mold capable of retaining moltenmaterial therein, means for applying said rotary drive to said lockedsections to rotate said mold about the mold axis, said rotary driveincluding a rotatable face plate having a plurality of radiallyextending channel-like apertures (87) that are each operable to secureone of said mold sections in juxtaposition to said face plate thereby toprevent axial movement of said mold sections while permitting radialmovement of the mold sections, means for pouring molten material intosaid rotating mold to cast a finned cylindrical structure therein, meansfor producing axial movement between said tapered lock ring means andsaid mold sections to release the radially inward force on saidsections, and means for actuating said drive means to apply a radialforce to said mold sections to strip said sections from said caststructure.
 15. A horizontal centrifugal casting machine according toclaim 14 wherein said lock ring means include two axially displacedrings each having a tapered radially inner face, means for traversingboth said rings simultanneously toward engagement with said moldsections to apply a predetermined radial force to said sections from atleast one said ring and resilient biasing means situated between atleast one of said rings and said traversing means to apply an axialforce to the associated ring tending to lock said ring against thetapered face of the mold section and balance the force applied by bothrings.
 16. A horizontal centrifugal casting machine according to claim15 further including means for circulating a fluid coolant in thermalcontact with the interior of said mold sections during casting of saidcylindrical structure.
 17. A horizontal centrifugal casting machine forcasting cylindrical structures comprising rotary drive means, aplurality of pulling means disposed at arcuately displaced locationsabout a central rotary axis, said pulling means having an extendablemember securable to an arcuate section of a cylindRical mold, means forextending the members of said pulling means to juxtapose said moldsegments thereby forming a cylindrical mold, means for transmittingtorque from said rotary drive to said cylindrical mold, means forpouring molten material into said rotating cylindrical mold tocentrifugally cast a cylindrical structure, means for inserting an arboraxially within said cylindrical structure, means for expanding saidarbor to contact the inner surface of said cast structure, means foractuating said pulling means to strip said arcuate sections from saidcast structure to isolate a finned cylindrical structure formed entirelyof solidified material, said stripping means radially displacing saidmold sections relative to said cast to dispose said stripped sectionsparallel to the disposition of said sections in the juxtaposed mold,means for axially moving the arbor and removing said cast cylindricalstructure from the interior of said mold sections, and means foractuating said pulling means to reassemble said mold sections into acylindrical mold.
 18. A horizontal centrifugal casting machine accordingto claim 17 wherein said pulling means are fixedly secured to anon-rotatable surface upon said casting machine, and further includingmeans for disengaging said pulling means from said mold sections priorto casting said cylindrical structure and axially traversable retainingring means movably mounted on said machine for maintaining said moldsections in juxtaposition upon disengagement of said pulling meanstherefrom.
 19. A horizontal centrifugal casting machine for castingfinned cylindrical structures comprising a first rotary drive, aplurality of radially movable arcuate sections, said sections beingcapable of forming a cylindrical mold upon a radially inward traversalof said sections to a juxtaposed position, reciprocal drive meanssecured to the outer periphery of said sections to position saidsections in a substantially cylindrical disposition, means for lockingsaid sections into a closed cylindrical mold, means for disengaging saidreciprocal drive means from said sections, means for applying saidrotary drive to said cylindrical mold, means for pouring molten materialinto said cylindrical mold during rotation of said mold, means fordisengaging said first rotary drive from said cylindrical mold, meansfor engaging a second rotary drive to said mold to rotate said mold at areduced speed relative to said first rotary drive, means for terminatingrotation of said mold at a predetermined angular position, means forengaging said reciprocal drive means with said mold sections and meansfor actuating said reciprocal drive means to apply a force perpendicularto the axis of said cylindrical mold to said sections to strip said moldsections from the structure cast within the mold.
 20. A horizontalcentrifugal casting machine comprising a plurality of arcuately shapedmold sections having longitudinally extending edges of complimentaryconfiguration to seat the edge of one mold section within the edge of anadjacent section upon juxtaposition of said sections into a cylindricalmold, means within said mold sections to secure said sections toradially movable jaws within the centrifugal casting machine, said jawsbeing adapted to receive molds of diverse diameter and having a taperedsurface along at least a portion of the outer periphery of the jaws,means for securing said jaws to pulling means mounted on the castingmachine, retaining ring means slidably mounted along the tapered surfaceof said jaws to apply radial force to said mold sections subsequent tothe juxtaposition of said sections, clamping means along the radiallyexterior face of said jaws to permit engagement of said jaws by pullingmeans, means for engaging and disengaging said pulling means from saidjaws, means for rotating said cylindrical mold, means for pouring moltenmaterial into the interior of said mold to cast a cylindrical structuretherein, means for terminating rotation of sAid mold at a predeterminedangular position to register said clamping means with said pullingmeans, means for advancing said pulling means into engagement with saidclamping means, means for releasing said retaining ring from said jawsand means for actuating said pulling means to radially strip said moldsections from said cast structure.